I started scanning the 200+ posts on this fuel and additives topic looking for some answers to my questions but gave up. So at the risk of opening up a well beaten subject here goes:

I will be running Shell V-Power in my 95 Mercury 4.6 2V for the next while. The questions I hope to answer are:

1. Will gas mileage improve (even slightly) because the car's engine control computer will make adjustments for the higher octane 91 (was running 87) ? The thinking here is that more volatility equals less volume of fuel required. Does the computer have this capability or does it just adjust only when it gets a knock signal ?

2. My go to gas was Pioneer which is not on the "Top Tier" list whereas Shell is. Shell and all Top Tier fuels, have more detergents which should help clean injectors, intake valves, comb. chambers, spark plugs, etc. Should I expect easier starts, smoother idle, better acceleration and the like ?

3. Probably the most compelling reason to try a 91 octane fuel is to eliminate ethanol use for my (older) car in particular. Much has been written on the pros and cons of ethanol and I am in the cons camp, mostly because of it's negative effects on fuel systems and engines. This is not really a question that can be readily answered by trial and observation. However, my research indicates that ethanol was introduced as a fuel supplement around 95/96. So my 95 car was not designed to use it. I don't know what design changes were made for E85 cars, so I don't know if ethanol is doing harm to my non-E85 vehicle. I guess that is kind of a question.

The 99 Camry had worse fuel economy. About 2 mpg less. I only did it to lock myself into Shell's Gold fuel reward status. I want to see if the 14 would have any increase with the 10.4:1 compression and Dual VVT.

I tried both 87 and 93 and didn't notice any difference in power or economy only thing i really noticed is weight reduction of my wallet. Shell gas in my state is lack luster anyway and can contain up to 20% ethanol on the regular pump.